Conventionally, standalone type keyboards (hardware keyboards) are being widely used as means for inputting characters into computers. However, in recent years, there have been situations where it is not possible to arrange a hardware keyboard as a result of that downsized electronic devices have become very popular, that the configuration and the operating environment of electronic devices have changed remarkably and that the design and the functionality of electronic devices have become relatively important. Additionally, as multi-functional electronic devices have become popular, input operations using only key buttons cannot cope with the multi-functionality of devices.
So-called contact input/detection techniques of directly touching icons and graphic images being displayed on the display (screen) of electronic device have effectively been used as input interface in addition to the use of hardware keyboards.
With contact input/detection, a pressure detection means is arranged on the display panel such as LCD (liquid display device) panel and keys are displayed on the display for inputting characters so that, as the user touches the display screen by means of a finger tip or an input pen, the pressure detection means detects it as pressure signal and selects the key that corresponds to the touched position of the display.
In the case of an electronic device such as a personal computer or a television receiving set having a relatively large display, however, the contact input/detection arrangement imposes a considerable load on the user because the user is forced to move the operating hand and the eyes to a large extent to contact and select an icon displayed on the display. Particularly, when an input pen is used, the user has to select each character to be input from the group of characters being displayed on the display and move the pen tip to touch the characters one by one on the display. Then, the efficiency of input operation may remarkably fall if compared with the input operation using a keyboard.
Additionally, there have been developed techniques with which the user writes characters or words on the display by means of an input pen and the device recognizes the written characters. However, it takes time for the electronic device to accurately recognize the written characters. In other words, the input efficiency of such a technique is as poor as the contact input/detection arrangement.
The input efficiency can be improved to provide the user with a multiple choice arrangement. For example, if the user writes “a”, the display screen may display “about”, “alone”, “at home”, “another” and other candidate words for the written “a” so that the user may select the right word he or she is trying to input form these candidate words. Such an input support function can be realized by means of software. However, the load imposed on the user is not remarkably alleviated because the user is required to repeat a sequence of operation of selecting the right word from the candidate words, moving the pen tip to the right word and making it touches the display.
A software keyboard that is operated by two hands like a hardware keyboard may be displayed on the display. However, then a considerable part of the display is occupied to display the software keyboard to annoy the user. Additionally, while the keyboard operation may be facilitated to the user, the problems relating to input operations remain unsolved because the display area becomes narrow.